1 #include "DwarfCompileUnit.h"
2 #include "DwarfExpression.h"
3 #include "llvm/CodeGen/MachineFunction.h"
4 #include "llvm/IR/DataLayout.h"
5 #include "llvm/IR/GlobalValue.h"
6 #include "llvm/IR/GlobalVariable.h"
7 #include "llvm/IR/Instruction.h"
8 #include "llvm/MC/MCAsmInfo.h"
9 #include "llvm/MC/MCStreamer.h"
10 #include "llvm/Target/TargetFrameLowering.h"
11 #include "llvm/Target/TargetLoweringObjectFile.h"
12 #include "llvm/Target/TargetMachine.h"
13 #include "llvm/Target/TargetRegisterInfo.h"
14 #include "llvm/Target/TargetSubtargetInfo.h"
18 DwarfCompileUnit::DwarfCompileUnit(unsigned UID, DICompileUnit Node,
19 AsmPrinter *A, DwarfDebug *DW,
21 : DwarfUnit(UID, dwarf::DW_TAG_compile_unit, Node, A, DW, DWU),
22 Skeleton(nullptr), BaseAddress(nullptr) {
23 insertDIE(Node, &getUnitDie());
26 /// addLabelAddress - Add a dwarf label attribute data and value using
27 /// DW_FORM_addr or DW_FORM_GNU_addr_index.
29 void DwarfCompileUnit::addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
30 const MCSymbol *Label) {
32 // Don't use the address pool in non-fission or in the skeleton unit itself.
33 // FIXME: Once GDB supports this, it's probably worthwhile using the address
34 // pool from the skeleton - maybe even in non-fission (possibly fewer
35 // relocations by sharing them in the pool, but we have other ideas about how
36 // to reduce the number of relocations as well/instead).
37 if (!DD->useSplitDwarf() || !Skeleton)
38 return addLocalLabelAddress(Die, Attribute, Label);
41 DD->addArangeLabel(SymbolCU(this, Label));
43 unsigned idx = DD->getAddressPool().getIndex(Label);
44 DIEValue *Value = new (DIEValueAllocator) DIEInteger(idx);
45 Die.addValue(Attribute, dwarf::DW_FORM_GNU_addr_index, Value);
48 void DwarfCompileUnit::addLocalLabelAddress(DIE &Die,
49 dwarf::Attribute Attribute,
50 const MCSymbol *Label) {
52 DD->addArangeLabel(SymbolCU(this, Label));
54 Die.addValue(Attribute, dwarf::DW_FORM_addr,
55 Label ? (DIEValue *)new (DIEValueAllocator) DIELabel(Label)
56 : new (DIEValueAllocator) DIEInteger(0));
59 unsigned DwarfCompileUnit::getOrCreateSourceID(StringRef FileName,
61 // If we print assembly, we can't separate .file entries according to
62 // compile units. Thus all files will belong to the default compile unit.
64 // FIXME: add a better feature test than hasRawTextSupport. Even better,
65 // extend .file to support this.
66 return Asm->OutStreamer.EmitDwarfFileDirective(
68 Asm->OutStreamer.hasRawTextSupport() ? 0 : getUniqueID());
71 // Return const expression if value is a GEP to access merged global
73 // i8* getelementptr ({ i8, i8, i8, i8 }* @_MergedGlobals, i32 0, i32 0)
74 static const ConstantExpr *getMergedGlobalExpr(const Value *V) {
75 const ConstantExpr *CE = dyn_cast_or_null<ConstantExpr>(V);
76 if (!CE || CE->getNumOperands() != 3 ||
77 CE->getOpcode() != Instruction::GetElementPtr)
80 // First operand points to a global struct.
81 Value *Ptr = CE->getOperand(0);
82 if (!isa<GlobalValue>(Ptr) ||
83 !isa<StructType>(cast<PointerType>(Ptr->getType())->getElementType()))
86 // Second operand is zero.
87 const ConstantInt *CI = dyn_cast_or_null<ConstantInt>(CE->getOperand(1));
88 if (!CI || !CI->isZero())
91 // Third operand is offset.
92 if (!isa<ConstantInt>(CE->getOperand(2)))
98 /// getOrCreateGlobalVariableDIE - get or create global variable DIE.
99 DIE *DwarfCompileUnit::getOrCreateGlobalVariableDIE(DIGlobalVariable GV) {
100 // Check for pre-existence.
101 if (DIE *Die = getDIE(GV))
106 DIScope GVContext = GV.getContext();
107 DIType GTy = DD->resolve(GV.getType());
109 // Construct the context before querying for the existence of the DIE in
110 // case such construction creates the DIE.
111 DIE *ContextDIE = getOrCreateContextDIE(GVContext);
114 DIE *VariableDIE = &createAndAddDIE(GV.getTag(), *ContextDIE, GV);
117 if (DIDerivedType SDMDecl = GV.getStaticDataMemberDeclaration()) {
118 DeclContext = resolve(SDMDecl.getContext());
119 assert(SDMDecl.isStaticMember() && "Expected static member decl");
120 assert(GV.isDefinition());
121 // We need the declaration DIE that is in the static member's class.
122 DIE *VariableSpecDIE = getOrCreateStaticMemberDIE(SDMDecl);
123 addDIEEntry(*VariableDIE, dwarf::DW_AT_specification, *VariableSpecDIE);
125 DeclContext = GV.getContext();
126 // Add name and type.
127 addString(*VariableDIE, dwarf::DW_AT_name, GV.getDisplayName());
128 addType(*VariableDIE, GTy);
131 if (!GV.isLocalToUnit())
132 addFlag(*VariableDIE, dwarf::DW_AT_external);
134 // Add line number info.
135 addSourceLine(*VariableDIE, GV);
138 if (!GV.isDefinition())
139 addFlag(*VariableDIE, dwarf::DW_AT_declaration);
142 bool addToAccelTable = false;
143 bool isGlobalVariable = GV.getGlobal() != nullptr;
144 if (isGlobalVariable) {
145 addToAccelTable = true;
146 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
147 const MCSymbol *Sym = Asm->getSymbol(GV.getGlobal());
148 if (GV.getGlobal()->isThreadLocal()) {
149 // FIXME: Make this work with -gsplit-dwarf.
150 unsigned PointerSize = Asm->getDataLayout().getPointerSize();
151 assert((PointerSize == 4 || PointerSize == 8) &&
152 "Add support for other sizes if necessary");
153 // Based on GCC's support for TLS:
154 if (!DD->useSplitDwarf()) {
155 // 1) Start with a constNu of the appropriate pointer size
156 addUInt(*Loc, dwarf::DW_FORM_data1,
157 PointerSize == 4 ? dwarf::DW_OP_const4u : dwarf::DW_OP_const8u);
158 // 2) containing the (relocated) offset of the TLS variable
159 // within the module's TLS block.
160 addExpr(*Loc, dwarf::DW_FORM_udata,
161 Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
163 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
164 addUInt(*Loc, dwarf::DW_FORM_udata,
165 DD->getAddressPool().getIndex(Sym, /* TLS */ true));
167 // 3) followed by an OP to make the debugger do a TLS lookup.
168 addUInt(*Loc, dwarf::DW_FORM_data1,
169 DD->useGNUTLSOpcode() ? dwarf::DW_OP_GNU_push_tls_address
170 : dwarf::DW_OP_form_tls_address);
172 DD->addArangeLabel(SymbolCU(this, Sym));
173 addOpAddress(*Loc, Sym);
176 addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
177 addLinkageName(*VariableDIE, GV.getLinkageName());
178 } else if (const ConstantInt *CI =
179 dyn_cast_or_null<ConstantInt>(GV.getConstant())) {
180 addConstantValue(*VariableDIE, CI, GTy);
181 } else if (const ConstantExpr *CE = getMergedGlobalExpr(GV.getConstant())) {
182 addToAccelTable = true;
183 // GV is a merged global.
184 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
185 Value *Ptr = CE->getOperand(0);
186 MCSymbol *Sym = Asm->getSymbol(cast<GlobalValue>(Ptr));
187 DD->addArangeLabel(SymbolCU(this, Sym));
188 addOpAddress(*Loc, Sym);
189 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
190 SmallVector<Value *, 3> Idx(CE->op_begin() + 1, CE->op_end());
191 addUInt(*Loc, dwarf::DW_FORM_udata,
192 Asm->getDataLayout().getIndexedOffset(Ptr->getType(), Idx));
193 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
194 addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
197 if (addToAccelTable) {
198 DD->addAccelName(GV.getName(), *VariableDIE);
200 // If the linkage name is different than the name, go ahead and output
201 // that as well into the name table.
202 if (GV.getLinkageName() != "" && GV.getName() != GV.getLinkageName())
203 DD->addAccelName(GV.getLinkageName(), *VariableDIE);
206 addGlobalName(GV.getName(), *VariableDIE, DeclContext);
210 void DwarfCompileUnit::addRange(RangeSpan Range) {
211 bool SameAsPrevCU = this == DD->getPrevCU();
213 // If we have no current ranges just add the range and return, otherwise,
214 // check the current section and CU against the previous section and CU we
215 // emitted into and the subprogram was contained within. If these are the
216 // same then extend our current range, otherwise add this as a new range.
217 if (CURanges.empty() || !SameAsPrevCU ||
218 (&CURanges.back().getEnd()->getSection() !=
219 &Range.getEnd()->getSection())) {
220 CURanges.push_back(Range);
224 CURanges.back().setEnd(Range.getEnd());
227 void DwarfCompileUnit::addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
228 const MCSymbol *Label,
229 const MCSymbol *Sec) {
230 if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
231 addLabel(Die, Attribute,
232 DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
233 : dwarf::DW_FORM_data4,
236 addSectionDelta(Die, Attribute, Label, Sec);
239 void DwarfCompileUnit::initStmtList() {
240 // Define start line table label for each Compile Unit.
241 MCSymbol *LineTableStartSym =
242 Asm->OutStreamer.getDwarfLineTableSymbol(getUniqueID());
244 stmtListIndex = UnitDie.getValues().size();
246 // DW_AT_stmt_list is a offset of line number information for this
247 // compile unit in debug_line section. For split dwarf this is
248 // left in the skeleton CU and so not included.
249 // The line table entries are not always emitted in assembly, so it
250 // is not okay to use line_table_start here.
251 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
252 addSectionLabel(UnitDie, dwarf::DW_AT_stmt_list, LineTableStartSym,
253 TLOF.getDwarfLineSection()->getBeginSymbol());
256 void DwarfCompileUnit::applyStmtList(DIE &D) {
257 D.addValue(dwarf::DW_AT_stmt_list,
258 UnitDie.getAbbrev().getData()[stmtListIndex].getForm(),
259 UnitDie.getValues()[stmtListIndex]);
262 void DwarfCompileUnit::attachLowHighPC(DIE &D, const MCSymbol *Begin,
263 const MCSymbol *End) {
264 assert(Begin && "Begin label should not be null!");
265 assert(End && "End label should not be null!");
266 assert(Begin->isDefined() && "Invalid starting label");
267 assert(End->isDefined() && "Invalid end label");
269 addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
270 if (DD->getDwarfVersion() < 4)
271 addLabelAddress(D, dwarf::DW_AT_high_pc, End);
273 addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
276 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
277 // and DW_AT_high_pc attributes. If there are global variables in this
278 // scope then create and insert DIEs for these variables.
279 DIE &DwarfCompileUnit::updateSubprogramScopeDIE(DISubprogram SP) {
280 DIE *SPDie = getOrCreateSubprogramDIE(SP, includeMinimalInlineScopes());
282 attachLowHighPC(*SPDie, Asm->getFunctionBegin(), Asm->getFunctionEnd());
283 if (!DD->getCurrentFunction()->getTarget().Options.DisableFramePointerElim(
284 *DD->getCurrentFunction()))
285 addFlag(*SPDie, dwarf::DW_AT_APPLE_omit_frame_ptr);
287 // Only include DW_AT_frame_base in full debug info
288 if (!includeMinimalInlineScopes()) {
289 const TargetRegisterInfo *RI = Asm->MF->getSubtarget().getRegisterInfo();
290 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
291 if (RI->isPhysicalRegister(Location.getReg()))
292 addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
295 // Add name to the name table, we do this here because we're guaranteed
296 // to have concrete versions of our DW_TAG_subprogram nodes.
297 DD->addSubprogramNames(SP, *SPDie);
302 // Construct a DIE for this scope.
303 void DwarfCompileUnit::constructScopeDIE(
304 LexicalScope *Scope, SmallVectorImpl<std::unique_ptr<DIE>> &FinalChildren) {
305 if (!Scope || !Scope->getScopeNode())
308 DIScope DS(Scope->getScopeNode());
310 assert((Scope->getInlinedAt() || !isa<MDSubprogram>(DS)) &&
311 "Only handle inlined subprograms here, use "
312 "constructSubprogramScopeDIE for non-inlined "
315 SmallVector<std::unique_ptr<DIE>, 8> Children;
317 // We try to create the scope DIE first, then the children DIEs. This will
318 // avoid creating un-used children then removing them later when we find out
319 // the scope DIE is null.
320 std::unique_ptr<DIE> ScopeDIE;
321 if (Scope->getParent() && isa<MDSubprogram>(DS)) {
322 ScopeDIE = constructInlinedScopeDIE(Scope);
325 // We create children when the scope DIE is not null.
326 createScopeChildrenDIE(Scope, Children);
328 // Early exit when we know the scope DIE is going to be null.
329 if (DD->isLexicalScopeDIENull(Scope))
332 unsigned ChildScopeCount;
334 // We create children here when we know the scope DIE is not going to be
335 // null and the children will be added to the scope DIE.
336 createScopeChildrenDIE(Scope, Children, &ChildScopeCount);
338 // Skip imported directives in gmlt-like data.
339 if (!includeMinimalInlineScopes()) {
340 // There is no need to emit empty lexical block DIE.
341 for (const auto &E : DD->findImportedEntitiesForScope(DS))
343 constructImportedEntityDIE(cast<MDImportedEntity>(E.second)));
346 // If there are only other scopes as children, put them directly in the
347 // parent instead, as this scope would serve no purpose.
348 if (Children.size() == ChildScopeCount) {
349 FinalChildren.insert(FinalChildren.end(),
350 std::make_move_iterator(Children.begin()),
351 std::make_move_iterator(Children.end()));
354 ScopeDIE = constructLexicalScopeDIE(Scope);
355 assert(ScopeDIE && "Scope DIE should not be null.");
359 for (auto &I : Children)
360 ScopeDIE->addChild(std::move(I));
362 FinalChildren.push_back(std::move(ScopeDIE));
365 void DwarfCompileUnit::addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
366 const MCSymbol *Hi, const MCSymbol *Lo) {
367 DIEValue *Value = new (DIEValueAllocator) DIEDelta(Hi, Lo);
368 Die.addValue(Attribute, DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
369 : dwarf::DW_FORM_data4,
373 void DwarfCompileUnit::addScopeRangeList(DIE &ScopeDIE,
374 SmallVector<RangeSpan, 2> Range) {
375 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
377 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
378 // emitting it appropriately.
379 const MCSymbol *RangeSectionSym =
380 TLOF.getDwarfRangesSection()->getBeginSymbol();
382 RangeSpanList List(Asm->createTempSymbol("debug_ranges"), std::move(Range));
384 // Under fission, ranges are specified by constant offsets relative to the
385 // CU's DW_AT_GNU_ranges_base.
387 addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
390 addSectionLabel(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
393 // Add the range list to the set of ranges to be emitted.
394 (Skeleton ? Skeleton : this)->CURangeLists.push_back(std::move(List));
397 void DwarfCompileUnit::attachRangesOrLowHighPC(
398 DIE &Die, SmallVector<RangeSpan, 2> Ranges) {
399 if (Ranges.size() == 1) {
400 const auto &single = Ranges.front();
401 attachLowHighPC(Die, single.getStart(), single.getEnd());
403 addScopeRangeList(Die, std::move(Ranges));
406 void DwarfCompileUnit::attachRangesOrLowHighPC(
407 DIE &Die, const SmallVectorImpl<InsnRange> &Ranges) {
408 SmallVector<RangeSpan, 2> List;
409 List.reserve(Ranges.size());
410 for (const InsnRange &R : Ranges)
411 List.push_back(RangeSpan(DD->getLabelBeforeInsn(R.first),
412 DD->getLabelAfterInsn(R.second)));
413 attachRangesOrLowHighPC(Die, std::move(List));
416 // This scope represents inlined body of a function. Construct DIE to
417 // represent this concrete inlined copy of the function.
419 DwarfCompileUnit::constructInlinedScopeDIE(LexicalScope *Scope) {
420 assert(Scope->getScopeNode());
421 DIScope DS(Scope->getScopeNode());
422 DISubprogram InlinedSP = getDISubprogram(DS);
423 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
424 // was inlined from another compile unit.
425 DIE *OriginDIE = DU->getAbstractSPDies()[InlinedSP];
426 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
428 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
429 addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
431 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
433 // Add the call site information to the DIE.
434 DILocation DL(Scope->getInlinedAt());
435 addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
436 getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
437 addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
439 // Add name to the name table, we do this here because we're guaranteed
440 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
441 DD->addSubprogramNames(InlinedSP, *ScopeDIE);
446 // Construct new DW_TAG_lexical_block for this scope and attach
447 // DW_AT_low_pc/DW_AT_high_pc labels.
449 DwarfCompileUnit::constructLexicalScopeDIE(LexicalScope *Scope) {
450 if (DD->isLexicalScopeDIENull(Scope))
453 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
454 if (Scope->isAbstractScope())
457 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
462 /// constructVariableDIE - Construct a DIE for the given DbgVariable.
463 std::unique_ptr<DIE> DwarfCompileUnit::constructVariableDIE(DbgVariable &DV,
465 auto D = constructVariableDIEImpl(DV, Abstract);
471 DwarfCompileUnit::constructVariableDIEImpl(const DbgVariable &DV,
473 // Define variable debug information entry.
474 auto VariableDie = make_unique<DIE>(DV.getTag());
477 applyVariableAttributes(DV, *VariableDie);
481 // Add variable address.
483 unsigned Offset = DV.getDotDebugLocOffset();
485 addLocationList(*VariableDie, dwarf::DW_AT_location, Offset);
489 // Check if variable is described by a DBG_VALUE instruction.
490 if (const MachineInstr *DVInsn = DV.getMInsn()) {
491 assert(DVInsn->getNumOperands() == 4);
492 if (DVInsn->getOperand(0).isReg()) {
493 const MachineOperand RegOp = DVInsn->getOperand(0);
494 // If the second operand is an immediate, this is an indirect value.
495 if (DVInsn->getOperand(1).isImm()) {
496 MachineLocation Location(RegOp.getReg(),
497 DVInsn->getOperand(1).getImm());
498 addVariableAddress(DV, *VariableDie, Location);
499 } else if (RegOp.getReg())
500 addVariableAddress(DV, *VariableDie, MachineLocation(RegOp.getReg()));
501 } else if (DVInsn->getOperand(0).isImm())
502 addConstantValue(*VariableDie, DVInsn->getOperand(0), DV.getType());
503 else if (DVInsn->getOperand(0).isFPImm())
504 addConstantFPValue(*VariableDie, DVInsn->getOperand(0));
505 else if (DVInsn->getOperand(0).isCImm())
506 addConstantValue(*VariableDie, DVInsn->getOperand(0).getCImm(),
512 // .. else use frame index.
513 if (DV.getFrameIndex().back() == ~0)
516 auto Expr = DV.getExpression().begin();
517 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
518 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
519 for (auto FI : DV.getFrameIndex()) {
520 unsigned FrameReg = 0;
521 const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering();
522 int Offset = TFI->getFrameIndexReference(*Asm->MF, FI, FrameReg);
523 assert(Expr != DV.getExpression().end() &&
524 "Wrong number of expressions");
525 DwarfExpr.AddMachineRegIndirect(FrameReg, Offset);
526 DwarfExpr.AddExpression((*Expr)->expr_op_begin(), (*Expr)->expr_op_end());
529 addBlock(*VariableDie, dwarf::DW_AT_location, Loc);
534 std::unique_ptr<DIE> DwarfCompileUnit::constructVariableDIE(
535 DbgVariable &DV, const LexicalScope &Scope, DIE *&ObjectPointer) {
536 auto Var = constructVariableDIE(DV, Scope.isAbstractScope());
537 if (DV.isObjectPointer())
538 ObjectPointer = Var.get();
542 DIE *DwarfCompileUnit::createScopeChildrenDIE(
543 LexicalScope *Scope, SmallVectorImpl<std::unique_ptr<DIE>> &Children,
544 unsigned *ChildScopeCount) {
545 DIE *ObjectPointer = nullptr;
547 for (DbgVariable *DV : DU->getScopeVariables().lookup(Scope))
548 Children.push_back(constructVariableDIE(*DV, *Scope, ObjectPointer));
550 unsigned ChildCountWithoutScopes = Children.size();
552 for (LexicalScope *LS : Scope->getChildren())
553 constructScopeDIE(LS, Children);
556 *ChildScopeCount = Children.size() - ChildCountWithoutScopes;
558 return ObjectPointer;
561 void DwarfCompileUnit::constructSubprogramScopeDIE(LexicalScope *Scope) {
562 assert(Scope && Scope->getScopeNode());
563 assert(!Scope->getInlinedAt());
564 assert(!Scope->isAbstractScope());
565 DISubprogram Sub = cast<MDSubprogram>(Scope->getScopeNode());
567 DD->getProcessedSPNodes().insert(Sub);
569 DIE &ScopeDIE = updateSubprogramScopeDIE(Sub);
571 // If this is a variadic function, add an unspecified parameter.
572 DITypeArray FnArgs = Sub.getType().getTypeArray();
574 // Collect lexical scope children first.
575 // ObjectPointer might be a local (non-argument) local variable if it's a
576 // block's synthetic this pointer.
577 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, ScopeDIE))
578 addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
580 // If we have a single element of null, it is a function that returns void.
581 // If we have more than one elements and the last one is null, it is a
582 // variadic function.
583 if (FnArgs.getNumElements() > 1 &&
584 !FnArgs.getElement(FnArgs.getNumElements() - 1) &&
585 !includeMinimalInlineScopes())
586 ScopeDIE.addChild(make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
589 DIE *DwarfCompileUnit::createAndAddScopeChildren(LexicalScope *Scope,
591 // We create children when the scope DIE is not null.
592 SmallVector<std::unique_ptr<DIE>, 8> Children;
593 DIE *ObjectPointer = createScopeChildrenDIE(Scope, Children);
596 for (auto &I : Children)
597 ScopeDIE.addChild(std::move(I));
599 return ObjectPointer;
603 DwarfCompileUnit::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
604 DIE *&AbsDef = DU->getAbstractSPDies()[Scope->getScopeNode()];
608 DISubprogram SP = cast<MDSubprogram>(Scope->getScopeNode());
612 if (includeMinimalInlineScopes())
613 ContextDIE = &getUnitDie();
614 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
615 // the important distinction that the DIDescriptor is not associated with the
616 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
617 // any). It could be refactored to some common utility function.
618 else if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
619 ContextDIE = &getUnitDie();
620 getOrCreateSubprogramDIE(SPDecl);
622 ContextDIE = getOrCreateContextDIE(resolve(SP.getContext()));
624 // Passing null as the associated DIDescriptor because the abstract definition
625 // shouldn't be found by lookup.
627 &createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, DIDescriptor());
628 applySubprogramAttributesToDefinition(SP, *AbsDef);
630 if (!includeMinimalInlineScopes())
631 addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
632 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, *AbsDef))
633 addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
637 DwarfCompileUnit::constructImportedEntityDIE(const DIImportedEntity &Module) {
638 std::unique_ptr<DIE> IMDie = make_unique<DIE>((dwarf::Tag)Module.getTag());
639 insertDIE(Module, IMDie.get());
641 DIDescriptor Entity = resolve(Module.getEntity());
642 if (auto *NS = dyn_cast<MDNamespace>(Entity))
643 EntityDie = getOrCreateNameSpace(NS);
644 else if (auto *SP = dyn_cast<MDSubprogram>(Entity))
645 EntityDie = getOrCreateSubprogramDIE(SP);
646 else if (auto *T = dyn_cast<MDType>(Entity))
647 EntityDie = getOrCreateTypeDIE(T);
648 else if (auto *GV = dyn_cast<MDGlobalVariable>(Entity))
649 EntityDie = getOrCreateGlobalVariableDIE(GV);
651 EntityDie = getDIE(Entity);
653 addSourceLine(*IMDie, Module.getLineNumber(),
654 Module.getContext().getFilename(),
655 Module.getContext().getDirectory());
656 addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
657 StringRef Name = Module.getName();
659 addString(*IMDie, dwarf::DW_AT_name, Name);
664 void DwarfCompileUnit::finishSubprogramDefinition(DISubprogram SP) {
666 if (DIE *AbsSPDIE = DU->getAbstractSPDies().lookup(SP)) {
668 // If this subprogram has an abstract definition, reference that
669 addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
671 if (!D && !includeMinimalInlineScopes())
672 // Lazily construct the subprogram if we didn't see either concrete or
673 // inlined versions during codegen. (except in -gmlt ^ where we want
674 // to omit these entirely)
675 D = getOrCreateSubprogramDIE(SP);
677 // And attach the attributes
678 applySubprogramAttributesToDefinition(SP, *D);
681 void DwarfCompileUnit::collectDeadVariables(DISubprogram SP) {
682 assert(SP && "CU's subprogram list contains a non-subprogram");
683 assert(SP.isDefinition() &&
684 "CU's subprogram list contains a subprogram declaration");
685 DIArray Variables = SP.getVariables();
686 if (Variables.getNumElements() == 0)
689 DIE *SPDIE = DU->getAbstractSPDies().lookup(SP);
693 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
694 DIVariable DV = cast<MDLocalVariable>(Variables.getElement(vi));
695 DbgVariable NewVar(DV, DIExpression(), DD);
696 auto VariableDie = constructVariableDIE(NewVar);
697 applyVariableAttributes(NewVar, *VariableDie);
698 SPDIE->addChild(std::move(VariableDie));
702 void DwarfCompileUnit::emitHeader(bool UseOffsets) {
703 // Don't bother labeling the .dwo unit, as its offset isn't used.
705 LabelBegin = Asm->createTempSymbol("cu_begin");
706 Asm->OutStreamer.EmitLabel(LabelBegin);
709 DwarfUnit::emitHeader(UseOffsets);
712 /// addGlobalName - Add a new global name to the compile unit.
713 void DwarfCompileUnit::addGlobalName(StringRef Name, DIE &Die,
715 if (includeMinimalInlineScopes())
717 std::string FullName = getParentContextString(Context) + Name.str();
718 GlobalNames[FullName] = &Die;
721 /// Add a new global type to the unit.
722 void DwarfCompileUnit::addGlobalType(DIType Ty, const DIE &Die,
724 if (includeMinimalInlineScopes())
726 std::string FullName = getParentContextString(Context) + Ty.getName().str();
727 GlobalTypes[FullName] = &Die;
730 /// addVariableAddress - Add DW_AT_location attribute for a
731 /// DbgVariable based on provided MachineLocation.
732 void DwarfCompileUnit::addVariableAddress(const DbgVariable &DV, DIE &Die,
733 MachineLocation Location) {
734 if (DV.variableHasComplexAddress())
735 addComplexAddress(DV, Die, dwarf::DW_AT_location, Location);
736 else if (DV.isBlockByrefVariable())
737 addBlockByrefAddress(DV, Die, dwarf::DW_AT_location, Location);
739 addAddress(Die, dwarf::DW_AT_location, Location);
742 /// Add an address attribute to a die based on the location provided.
743 void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
744 const MachineLocation &Location) {
745 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
748 if (Location.isReg())
749 validReg = addRegisterOpPiece(*Loc, Location.getReg());
751 validReg = addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
756 // Now attach the location information to the DIE.
757 addBlock(Die, Attribute, Loc);
760 /// Start with the address based on the location provided, and generate the
761 /// DWARF information necessary to find the actual variable given the extra
762 /// address information encoded in the DbgVariable, starting from the starting
763 /// location. Add the DWARF information to the die.
764 void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
765 dwarf::Attribute Attribute,
766 const MachineLocation &Location) {
767 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
768 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
769 assert(DV.getExpression().size() == 1);
770 DIExpression Expr = DV.getExpression().back();
772 if (Location.getOffset()) {
773 ValidReg = DwarfExpr.AddMachineRegIndirect(Location.getReg(),
774 Location.getOffset());
776 DwarfExpr.AddExpression(Expr->expr_op_begin(), Expr->expr_op_end());
778 ValidReg = DwarfExpr.AddMachineRegExpression(Expr, Location.getReg());
780 // Now attach the location information to the DIE.
782 addBlock(Die, Attribute, Loc);
785 /// Add a Dwarf loclistptr attribute data and value.
786 void DwarfCompileUnit::addLocationList(DIE &Die, dwarf::Attribute Attribute,
788 DIEValue *Value = new (DIEValueAllocator) DIELocList(Index);
789 dwarf::Form Form = DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
790 : dwarf::DW_FORM_data4;
791 Die.addValue(Attribute, Form, Value);
794 void DwarfCompileUnit::applyVariableAttributes(const DbgVariable &Var,
796 StringRef Name = Var.getName();
798 addString(VariableDie, dwarf::DW_AT_name, Name);
799 addSourceLine(VariableDie, Var.getVariable());
800 addType(VariableDie, Var.getType());
801 if (Var.isArtificial())
802 addFlag(VariableDie, dwarf::DW_AT_artificial);
805 /// Add a Dwarf expression attribute data and value.
806 void DwarfCompileUnit::addExpr(DIELoc &Die, dwarf::Form Form,
807 const MCExpr *Expr) {
808 DIEValue *Value = new (DIEValueAllocator) DIEExpr(Expr);
809 Die.addValue((dwarf::Attribute)0, Form, Value);
812 void DwarfCompileUnit::applySubprogramAttributesToDefinition(DISubprogram SP,
814 DISubprogram SPDecl = SP.getFunctionDeclaration();
815 DIScope Context = resolve(SPDecl ? SPDecl.getContext() : SP.getContext());
816 applySubprogramAttributes(SP, SPDie, includeMinimalInlineScopes());
817 addGlobalName(SP.getName(), SPDie, Context);
820 bool DwarfCompileUnit::isDwoUnit() const {
821 return DD->useSplitDwarf() && Skeleton;
824 bool DwarfCompileUnit::includeMinimalInlineScopes() const {
825 return getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly ||
826 (DD->useSplitDwarf() && !Skeleton);
828 } // end llvm namespace